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Amiga 500 Restoration

About 6 weeks ago I got the somewhat crazy idea to — just for fun — play some Amiga games. At first, my plan was to set up a Raspberry Pi 3 with an Amiga emulator, after stumbling across Dan Wood’s YouTube channel. Even though I even have a Pi 3 lying around unused at the moment, seeing Dan holding that Amiga 500 in his hands at the beginning of the video, I got all nostalgic and decided I could at least do a quick ebay search to see how much they go for these days.

Turns out, I could get my hands on one, including a memory expansion card, mouse and power brick (and a brick it is!) for just 60€. Turns out, I would end up spending quite a bit more in the end, but still it was (and still is) a fun experience.

The whole story is probably way too long for a single post, so I may end up splitting this into at least two parts, but I feel it is necessary to write this down if only to remind myself about it in the future :-)

This is the first post in a series about restoring an Amiga 500 back to its former glory. Here are all of them so far. I’ll try to remember to update this in all related entry.

The Amiga 500

There’s quite a few Amigas on ebay, especially 500s. Considering they were the cheapest and thereby most common model, that makes sense. I god hold of one for 60€ plus shipping. I could have gotten one in better condition for more money, but I wanted something to try the technique of retrobrighting on, so I was just fine with the yellowed case.

It arrived in a big box with lots of packing paper, covering the mouse, the power brick and the Amiga itself, plus some cable I couldn’t immediately identify. Only later did I remember it is an RGB video cable. I also did not remember the power brick to be so heavy. It was equally yellowed.

The picture above was taken under fluorescent light, so the color representation is not exactly accurate. The next photo was taken in daylight on an overcast winter day, with a white sheet of paper for reference. I then used Photos.app on the Mac to set the white point to that paper. This allows a better side-by-side comparison later.

Having neither a suitable Amiga monitor like the venerable Commodore 1084S, nor an adapter cable to hook the machine up to my Panasonic plasma TV via the SCART connector, I could only do a very superficial health check. I hooked the computer up to power and turned it on. After about three seconds the power LED hat come up to full brightness, and the disk drive began its expected regular soft clicking every two seconds or so, looking for a 3.5” floppy. So the machine seemed healthy for the moment.

Cleaning inside and out

While the yellowed case is a consequence of age and UV exposure and cannot be removed superficially, there was also quite a bit of dirt and grime on the case, the keyboard, the mouse and the power brick. So I decided to take everything apart and give it a thorough cleaning. What follows are the steps to disassemble and clean everything.

Taking off the top case

The top case can easily be removed by unscrewing 6 screws on the underside. On some Amigas these may be Philips heads, but the more common variant seems to be with Torx screw heads. With a little care you can open them with a flat head screw driver, without damaging the screws. If you have the appropriate Torx screw driver, even better, of course.

On left and right side there are plastic clips on the inside, holding the top and bottom case together. Be careful when taking off the top part, because they are easy to break. Carefully wiggle the top case left and right to get one of them to slip out.

Once open, you have the keyboard and the RF shield in front of you. Be very gentle when handling the top case. Even though is won’t break apart too easily, due to the big holes for the keyboards, it lacks a bit of structural integrity unless handled by holding it on the more massive part where the ventilation slits are. Also take care to put it down gently and on soft undergrounds. I learned the hard way and chipped the two rear corners when trying to lean it against a wall and hit the ground at a bad angle.

Removing the Keyboard

To clean the keyboard, I recommend first removing it from the case. It has to come out for the later steps anyway. To do so, disconnect the cable from the motherboard by pulling it straight up through the hole in the shield. It should be rather safe to pull on the cable — the connector isn’t that tight on the board, and trying to get your fingers or some tool through the hole is probably a bigger risk of damaging something.

Don’t worry, the cable is keyed, so you don’t have to write down the orientation: Looking at it from above, there are 4 wires on the left, and 3 on the right, separated by an empty slot. The connector on the board has a missing pin there, too, so it is easy to reattach later.

Once the cable is free, you can slide the keyboard slightly from under the plastic latches at the very front of the machine. Then just lift it up. Notice the small spongy tape pieces between the keyboard metal base plate and the plastic latches. Depending on the age and condition of the Amiga, those might come off. In my case, the outer two stayed in place, the middle latches didn’t have any. I am not sure, if there used to be four. If they detach, I recommend replacing them, because I suppose they are intended to keep the keyboard more silent and as a strain relief for the plastic latches.

On right hand side, just beneath the power / drive LEDs, the keyboard rests on a similar little sponge. This one came right off when I lifted the keyboard up. This one, too, should be replaced, even though, of course, none of them are exactly mission critical. I did that with two layers of Powerstrips, leaving the protective tape on on the upper side.

Please note, that I only applied this at the very end of the restoration process, because in the meantime the Amiga casing underwent several other steps, which would have removed or at least damaged that new cushion.

When putting the keyboard back in later, carefully slide it back under the front latches. The metal base plate has a notch indicating the middle. Align that with the screw hole in the bottom case.

Removing the Key Caps

Lots of grime and dirt accumulates on and especially under the keys. To clean the keyboard thoroughly, the caps must be removed. The regular sized keys (including the F-Keys, Del, Help and Ctrl) can be taken off more easily than the larger ones (Return, Shift, the Spacebar, etc). You will often find people recommending to use a flat head screw driver to slide under a key cap, using it as a lever to pop the key off. While this works, I do not recommend it. The reason is that screw drivers are metal, and the key caps are 30 year old plastic, which got somewhat brittled over time. I learned the hard way that you cannot always tell how much force you can apply, before something breaks. This meant I had to repair a cracked “J” key (Super glue from the inside of the key was used to put the broken piece back in place. Once it had dried, two additional layers of flexible glue were added to increase stability).

What I found worked way better than metal were wooden skewers. They are flexible and tend to break when you apply too much pressure. I managed to get all remaining keys off without any more damage using this method.

This picture shows the the little hill each key rests on, as it stands above the plastic base. Having that before beginning would have helped a lot to understand where to apply force, so I’ll post this here for posterity. To get a key off, I tried to get two skewers underneath as shown by the parallel lines, and then to gently lift them upwards a little bit one at a time, alternating between the two. Most keys came of after just a few nudges. Be patient, they will eventually come loose. Some particularly stubborn ones took a few broken skewers. If they don’t seem to move at all, try to put a skewer close to the middle and carefully lift there. The thing that I found to be most important was to get the skewers to rest on the elevated part.

Underneath each of the regular sized keys, there is one metal spring. Be careful not to lose any, they make the keys come back up while typing. I placed them in a bin with a lid for safekeeping.

The bigger keys are a little more difficult to remove. They have metal braces underneath them to give them more stability and prevent wobbling. They can be popped off using the skewers, too, but you cannot just lift them off the keyboard afterwards. Instead, the braces need to be carefully removed either from the black plastic keyboard base, of from the key cap themselves.

I went for what I now consider the worse option and unclipped them from the base plate. In retrospect I think this is too risky, because for once at least some of them were really hard to get unclipped and you risk breaking off pieces of the assembly. Second, because you must be very gentle and not bend the braces. So if I were to do this again, I would use tweezers and unhook them from the underside of the key caps, which might be a little more fiddly, but requires much less force.

The pictures show the braces for the Return key, and where they are attached to the base plate, and on the underside of the key.

The space bar has three springs. Notice that the middle one is the same size as all the other keys, but those on the left and right of it are slightly shorter. This is important when reassembling the keyboard later.

Cleaning the Keyboard Base Plate

Once all the keys were taken off, this is what my keyboard base plate looked like. All in all not too gross, mostly lost of dust and some sticky stuff.

The first round of cleaning was just a brush and a handheld vacuum cleaner. This got rid of most of the dust and loose dirt. In my case, there was nothing left on the keyboard that could have been sucked into the vacuum, so I was not all to careful when doing this. If you leave the metal braces on there, make sure those are not ripped off.

Finally I used paper towels and warm water to remove everything that more sticky, and finally went around all the key domes and the nooks and crannies of the metal brace holders with isopropyl alcohol and cotton swabs. The end result looked like this:

Cleaning the Keyboard Caps

There was no glory in cleaning the key caps. They very unceremoniously were all dropped into a small bucket with warm water and some dish cleaning liquid to soak for a few minutes. After that came the laborious manual part, rubbing them with a kitchen sponge. Make sure to only use the soft parts of the sponge, should yours have a more scratchy side. That one would most probably leave visible marks in the otherwise very smooth plastic.

Some of the key caps had some nasty stuff stuck on the bottom side, which I had to remove with a tooth pick. The whole cleaning easily lasted for 30 minutes, because I wanted to make sure all sides of the keys were thoroughly cleaned in preparation for bleaching them later. The photo above shows how much the keys had yellowed, especially when you look at the space bar. You can clearly make out where the adjacent keys had kept light away from the side of it. Their shape is clearly visible in the “whiter” parts. Well will come back to this later.

Cleaning the RF shield

With the keyboard out, the RF shield is the most visible part now. I gave it the same treatment with brush and vacuum cleaner from the outside, including the space between it and the bottom case. This removed most of the dirt already. Then, with it still in the case, I wiped it off with a moistened paper towel and some glass cleaner. The dark spots seen in the photo are rust, so they can't be removed easily.

Removing the RF shield

The get to the mainboard, next I removed the RF shield from the case. It is attached to the bottom case just a few screws that are easy to get to. On the left, there is a separate metal bracket across the expansion port. I carefully removed that, too, and put it away to prevent it from getting bent.

To actually take the shield out, a series of small metal latches need to be bent upwards. They connect the metal tray the mainboard sits on with the RF shield. I just followed the edges of the RF shield and carefully bent them upwards with a flat head screwdriver.

Once they are all bent up, the shield came off with a little wiggling. Once out of the case, the shield is rather wobbly and should be put away safely to prevent accidental bending and deformation.

Cleaning the mainboard

With the RF shield out, the mainboard lay before me, with fond memories from the 80s… and with lots of dirt, potentially also from the 80s…

Again, this was cleaned with a brush and the handheld vacuum cleaner. Even though with the perspective in the photo does not really show it, I took particular care to not get the vacuum too close to the board, because I did not want to risk it ripping anything off the board (even though it was set to low power), and also to prevent too much electrostatic buildup.

It took a while, but I was pleased with the result.

Somewhere along the way I removed the floppy drive, because it covered part of the board.

Removing the mainboard

With the mainboard now clean, I removed it from the case, too, to be able to clean the bottom case. The board sits on a metal tray, which makes removal quite simple. The only thing to be careful about is to pull the board a little forward to get the external connectors free from their openings in the back wall of the plastic case. Once they are clear, the whole tray can be taken out. I also took the mainboard out of the tray for a moment, to be able to clean out the dust from underneath it. Once that was done, I put it back immediately, because it serves as a good protection for the bottom side of the board.

Cleaning the case parts

With everything removed from the case, I scrubbed the top and bottom cases with warm water, soap, an old toothbrush, paper towels, isopropyl alcohol, and microfibre cloths. Only for a very few stubborn spots I had to rub a little harder with some mild abrasive. That’s the white stuff you can see on one of the photos. Once done, I rinsed everything off in the shower and let it dry over night. While there are pictures of the dirty state, for some reason I did not think of documenting the finished cleaned state 🤨

At this point, I could have have just reassembled everything in reverse order, and frankly, that would have been a much better state than before. However, there were a few more things I had in mind. But those will be the topic of another post.

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